This invention relates to systems and methods for providing and managing Internet protocol (IP) connection oriented services.
The Internet Protocol was initially defined for connectionless services. These services normally operate on a best effort basis. There is now a keen interest in the provision of voice services over the Internet where costs are significantly less than those associated with the conventional PSTN. However, the adaptation of what is effectively a high priority connection oriented service to a xe2x80x98best effortxe2x80x99 connectionless or packet system has introduced a number of significant problems. In particular, if an Internet voice service is to obtain universal acceptance, it must provide a quality of service similar to that currently provided by conventional voice networks.
A number of workers are currently addressing this problem. For example, the current Internet Ipv4 protocol includes a TOS (type of service) octet, and Ipv6 a traffic class octet which allows a number of priority levels to be defined to support some degree of traffic engineering in an IP network. The IETF Differentiated Services Working Group has recently defined a method whereby traffic is classified at a priority level and is policed on entry to an IP network. Traffic behaviour on internal links (per hop behaviour) is specified. It is expected that using these methods then service level agreements can be offered to users provided that the number of internal hops is low and also provided that the percentage of high priority traffic is a small percentage of the total traffic.
Other IETF Working Groups have defined protocols providing some degree of connection orientation. These are:
Multi Protocol Label Switching (MPLS) includes the ability to tunnel through many routing stages and to do so using explicit routing rather than hop-by-hop routing. This is a form of connection orientation.
Layer 2 Tunnelling Protocol (LTP) provides a signalling system to dynamically create and delete IP point to point protocol (PPP) sessions end to end across a tunnel. These sessions are allocated bandwidth, are timed for billing purposes, and are explicitly deleted on completion. This is a fully connection oriented paradigm.
Connection orientation is of particular value in the provision of carrier network services to individual users or to user networks. In particular it simplifies the tasks of:
Guaranteeing bandwidth.
Ensuring Quality of service.
Authenticating end user identities.
Preventing fraudulent access or misuse of resources.
Existing Layer 2 networks such as Frame Relay or ATM are able to provide an effective control framework to provide bandwidth accounting however their control protocols are not sufficiently integrated into the Layer 3 IP network functionality to ensure that QoS characteristics of user services are maintained. This has limited the exploitation of this characteristic and has thus failed to resolve the provision of QoS in the Internet.
Reference is here directed to our co-pending application of even date (reference ID1068), the contents of which are incorporated herein by reference, which relates to a network architecture in which a network of layer 2 protocol (L2TP) tunnel switches provides an end of end connection oriented operation for PPP sessions.
An object of the invention is to minimise or to overcome the above disadvantage.
In addition it is recognised that ITU Signalling System No 7 (SS7) is of considerable value in Voice over IP networks as it allows access to Intelligent Network applications of the PSTN/ISDN and also provides service transparency whereby services such as Call Waiting can operate consistently for ISDN to ISDN, VoIP to ISDN and VoIP to VoIP calls.
In a first aspect, the invention provides an arrangement for providing voice and media service components over an IP network incorporating a plurality of nodes and in which connection oriented traffic is transported in tunnels via said nodes, the arrangement comprising means for providing signalling between said nodes, and means for multiplexing the voice and media components to form a point to point protocol (PPP) session, and means for switching said PPP session end to end across the network under the control of said signalling.
In another aspect, the invention provides a method of providing voice and media service components over an IP network incorporating a plurality of nodes, the method comprising providing signalling between said nodes, and multiplexing the voice and media components to form a point to point protocol (PPP) session which session is switched end to end across the network under the control of said signalling.
Preferably, the signalling comprises SS7 signalling.
Typically, the network tunnels comprise Layer 2 Tunnelling Protocol (L2TP) tunnels and Multi Protocol Label Switching (MPLS) tunnels.
In a preferred embodiment, gatekeepers are provided at either end of each tunnel so as to control the number of calls admitted to that tunnel. This enables the provision of quality of service guarantees to the admitted traffic.
This invention thus provides a network architecture for Voice over IP services in which e.g. SS7 signalling is used between Voice over IP nodes and the media components between the VoIP terminals are multiplexed to form a PPP Session which is switched end to end across the wide area network.